Question Unusual beeps before POST - ASUS Prime B350M-A

[unfa]

My PC recently is making very strange, elaborate beeps before post shows up.

I'd describe the sequence as as:
long + short + pause + medium + short


Here's a recording of the beeps:

View: https://youtu.be/j0DL2txUiTY


I've been looking for some information what could they mean - but I didn't find any matching descriptions.
I've searched my UEFI BIOS for any warnings, but it doesn't show anything unusual.
I am having some other issues (with disks) but I don't know if this is related or not.
I've been recently adding another 2 sticks of RAM for the total of 4, and I've done an extensive Memtest - no issues.
Then after a week or two the PC started beeping on POSTS (IIRC).

The machine is comprised of:

ASUS Prime B350M-A
Ryzen 7 1700
32 GB of RAM (4 x 8 GB)
Nvidia GTX 1060 6GB
Transcend M.2 256 GB SSD
(various HDDs, as the main HDD is going out on an RMA as soon as I copy and sanitize it)

These beeps occur about 90% of times I run the machine (even when it's only being resumed from sleep). I initially though it's related to a faulty HDD, but I now have disconnected all HDDs and the beeps are still there.

Does anybody know what could this beep sequence mean?

 

[trandaa]

Could be dead CMOS battery. You can try to check the time in BIOS (and set it to the right one if necessary), then turn off the PC, and unplug it from the wall. Let it be for few minutes (press the power button few times for sure that there's no electricity remaining). Plug it back turn it on and check in BIOS if the time is still right or it's reset to some default values.
If it resets to some default (wrong) time, your CMOS battery needs to be replaced (the big button battery on the MoBo, check the manual how to remove it)

 

[unfa]

Thanks! The motherboard is not older than two years, but I'll check it anyway.

 

[unfa]

Ok , I've checked this, and the UEFI BIOS clock didn't reset, nor any of the settings.
Looks like the battery is fine, but the system still beeps at around 50% of power-on events.

I'm gonna try and contact ASUS tech support about this.